diff --git a/r/R/query-engine.R b/r/R/query-engine.R
index 8d87fa1be1678..860d947cd48e4 100644
--- a/r/R/query-engine.R
+++ b/r/R/query-engine.R
@@ -224,13 +224,7 @@ ExecPlan <- R6Class("ExecPlan",
     Stop = function() ExecPlan_StopProducing(self)
   ),
   private = list(
-    .set_aggregation = function(node, data, grouped, group_vars) {
-      # Project to include just the data required for each aggregation,
-      # plus group_by_vars (last)
-      # TODO: validate that none of names(aggregations) are the same as names(group_by_vars)
-      # dplyr does not error on this but the result it gives isn't great
-      node <- node$Project(summarize_projection(data))
-
+    .set_aggregate_func_names = function(data, grouped) {
       if (grouped) {
         # We need to prefix all of the aggregation function names with "hash_"
         data$aggregations <- lapply(data$aggregations, function(x) {
@@ -238,16 +232,9 @@ ExecPlan <- R6Class("ExecPlan",
           x
         })
       }
-      target_names <- names(data$aggregations)
-      for (i in seq_len(length(target_names))) {
-        data$aggregations[[i]][["name"]] <- data$aggregations[[i]][["target"]] <- target_names[i]
-      }
-
-      node <- node$Aggregate(
-        options = data$aggregations,
-        key_names = group_vars
-      )
-
+      data
+    },
+    .set_group_by = function(node, data, group_vars, grouped) {
       if (grouped) {
         # The result will have result columns first then the grouping cols.
         # dplyr orders group cols first, so adapt the result to meet that expectation.
@@ -264,6 +251,27 @@ ExecPlan <- R6Class("ExecPlan",
         }
       }
       return(list(node = node, data = data))
+    },
+    .set_aggregation = function(node, data, grouped, group_vars) {
+      # Project to include just the data required for each aggregation,
+      # plus group_by_vars (last)
+      # TODO: validate that none of names(aggregations) are the same as names(group_by_vars)
+      # dplyr does not error on this but the result it gives isn't great
+      node <- node$Project(summarize_projection(data))
+
+      data <- private$.set_aggregate_func_names(data, grouped)
+
+      target_names <- names(data$aggregations)
+      for (i in seq_len(length(target_names))) {
+        data$aggregations[[i]][["name"]] <- data$aggregations[[i]][["target"]] <- target_names[i]
+      }
+
+      node <- node$Aggregate(
+        options = data$aggregations,
+        key_names = group_vars
+      )
+      group_config <- private$.set_group_by(node, data, group_vars, grouped)
+      return(list(node = group_config$node, data = group_config$data))
     }
   )
 )