diff --git a/DESCRIPTION b/DESCRIPTION
index 9fd22ad..b18d5af 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -37,7 +37,7 @@ URL: https://github.com/KevinSee/PITcleanr,
 BugReports: https://github.com/KevinSee/PITcleanr/issues
 Encoding: UTF-8
 LazyData: true
-RoxygenNote: 7.2.3
+RoxygenNote: 7.3.1
 Suggests: 
     ggrepel,
     kableExtra,
diff --git a/R/addParentChildNodes.R b/R/addParentChildNodes.R
index 1c987ca..dadb9d5 100644
--- a/R/addParentChildNodes.R
+++ b/R/addParentChildNodes.R
@@ -8,6 +8,7 @@
 #'
 #' @param parent_child dataframe produced by `buildParentChild()`.
 #' @param configuration a configuration dataframe, such as one built by `buildConfig()`.
+#' @inheritParams buildConfig
 #'
 #' @import dplyr tidyr stringr
 #' @return NULL
@@ -15,24 +16,44 @@
 #' @examples addParentChildNodes()
 
 addParentChildNodes = function(parent_child = NULL,
-                               configuration = NULL) {
+                               configuration = NULL,
+                               array_suffix = c("UD",
+                                                "UMD",
+                                                "A0B0")) {
   stopifnot(!is.null(parent_child),
             !is.null(configuration))
 
+  array_suffix = match.arg(array_suffix)
+
   # get the nodes for all site codes in the parent-child table
-  node_long = tibble(site_code = union(parent_child$child,
+  if(array_suffix %in% c("UD", "UMD")) {
+   node_site <-
+     configuration %>%
+     select(node) %>%
+     distinct() %>%
+     mutate(site_code = case_when(stringr::str_detect(node, "_D$") &
+                                    nchar(node) >= 5 ~ stringr::str_remove(node, "_D$"),
+                                  stringr::str_detect(node, "_U$") &
+                                    nchar(node) >= 5 ~ stringr::str_remove(node, "_U$"),
+                                  stringr::str_detect(node, "_M$") &
+                                    nchar(node) >= 5 ~ stringr::str_remove(node, "_M$"),
+                                  .default = node))
+  } else {
+    node_site <-
+      configuration %>%
+      select(node) %>%
+      distinct() %>%
+      mutate(site_code = case_when(stringr::str_detect(node, "B0$") &
+                                     nchar(node) >= 5 ~ stringr::str_remove(node, "B0$"),
+                                   stringr::str_detect(node, "A0$") &
+                                     nchar(node) >= 5 ~ stringr::str_remove(node, "A0$"),
+                                   .default = node))
+  }
+
+  node_long <-
+    tibble(site_code = union(parent_child$child,
                                        parent_child$parent)) %>%
-    left_join(configuration %>%
-                select(node) %>%
-                distinct() %>%
-                mutate(site_code = if_else(stringr::str_detect(node, "_D$") &
-                                             nchar(node) >= 5,
-                                           stringr::str_remove(node, "_D$"),
-                                           node),
-                       site_code = if_else(stringr::str_detect(site_code, "_U$") &
-                                             nchar(site_code) >= 5,
-                                           stringr::str_remove(site_code, "_U$"),
-                                           site_code)),
+    left_join(node_site,
               by = "site_code") %>%
     distinct() %>%
     arrange(site_code, node) %>%
diff --git a/man/addParentChildNodes.Rd b/man/addParentChildNodes.Rd
index 2f36f8e..b01a735 100644
--- a/man/addParentChildNodes.Rd
+++ b/man/addParentChildNodes.Rd
@@ -4,12 +4,21 @@
 \alias{addParentChildNodes}
 \title{Add Nodes to Parent-Child Table}
 \usage{
-addParentChildNodes(parent_child = NULL, configuration = NULL)
+addParentChildNodes(
+  parent_child = NULL,
+  configuration = NULL,
+  array_suffix = c("UD", "UMD", "A0B0")
+)
 }
 \arguments{
 \item{parent_child}{dataframe produced by `buildParentChild()`.}
 
 \item{configuration}{a configuration dataframe, such as one built by `buildConfig()`.}
+
+\item{array_suffix}{if \code{node_assign = "array"}, should nodes uses the suffixes of _U & _D (\code{UD}),
+_U, _M, & _D (\code{UMD}), or _A0 & _B0 (\code{A0B0}) to denote upstream, middle, and downstream arrays, respectively.
+Default is \code{UD}. If \code{array_suffix = "UD"} or \code{array_suffix = "A0B0"}, the middle array is grouped
+with the upstream array.}
 }
 \description{
 When some sites in the parent-child table have multiple nodes, this function