fix: show bt relation of self-link under system fields

packages/nc-gui/components/smartsheet/column/FormulaOptions.vue

@@ -37,7 +37,7 @@ const supportedColumns = computed(
         return false
       }
 
-      if (isHiddenCol(col)) {
+      if (isHiddenCol(col, meta.value)) {
         return false
       }
 

packages/nc-gui/components/smartsheet/toolbar/CreateGroupBy.vue

@@ -32,7 +32,7 @@ const options = computed<ColumnType[]>(
             return false
           }
 
-          if (isHiddenCol(c)) {
+          if (isHiddenCol(c, meta.value)) {
             /** ignore mm relation column, created by and last modified by system field */
             return false
           }

packages/nc-gui/components/smartsheet/toolbar/CreateSort.vue

@@ -27,7 +27,7 @@ const options = computed<ColumnType[]>(
           return true
         }
         if (isSystemColumn(metaColumnById?.value?.[c.id!])) {
-          if (isHiddenCol(c)) {
+          if (isHiddenCol(c,meta.value)) {
             /** ignore mm relation column, created by and last modified by system field */
             return false
           }

packages/nc-gui/components/smartsheet/toolbar/FieldListAutoCompleteDropdown.vue

@@ -39,7 +39,7 @@ const options = computed<SelectProps['options']>(() =>
       }
 
       if (isSystemColumn(metaColumnById?.value?.[c.id!])) {
-        if (isHiddenCol(c)) {
+        if (isHiddenCol(c,meta.value)) {
           /** ignore mm relation column, created by and last modified by system field */
           return false
         }
@@ -60,7 +60,7 @@ const options = computed<SelectProps['options']>(() =>
         return true
       }
       if (isSystemColumn(metaColumnById?.value?.[c.id!])) {
-        if (isHiddenCol(c)) {
+        if (isHiddenCol(c, meta.value)) {
           /** ignore mm relation column, created by and last modified by system field */
           return false
         }

packages/nc-gui/composables/useViewColumns.ts

@@ -87,7 +87,7 @@ const [useProvideViewColumns, useViewColumns] = useInjectionState(
         fields.value = meta.value?.columns
           ?.filter((column: ColumnType) => {
             // filter created by and last modified by system columns
-            if (isHiddenCol(column)) return false
+            if (isHiddenCol(column, meta.value)) return false
             return true
           })
           .map((column: ColumnType) => {

packages/nocodb-sdk/src/lib/UITypes.ts

@@ -1,5 +1,6 @@
-import { ColumnReqType, ColumnType } from './Api';
+import { ColumnReqType, ColumnType, TableType } from './Api';
 import { FormulaDataTypes } from './formulaHelpers';
+import { RelationTypes } from '~/lib/globals';
 
 enum UITypes {
   ID = 'ID',
@@ -208,17 +209,25 @@ export function isCreatedOrLastModifiedByCol(
 }
 
 export function isHiddenCol(
-  col: (ColumnReqType | ColumnType) & { system?: number | boolean }
+  col: (ColumnReqType | ColumnType) & {
+    colOptions?: any;
+    system?: number | boolean;
+  },
+  tableMeta: Partial<TableType>
 ) {
-  return (
-    col.system &&
-    (
-      [
-        UITypes.CreatedBy,
-        UITypes.LastModifiedBy,
-        UITypes.LinkToAnotherRecord,
-      ] as string[]
-    ).includes(col.uidt)
+  if (!col.system) return false;
+
+  // hide belongs to column in mm tables only
+  if (col.uidt === UITypes.LinkToAnotherRecord) {
+    if (col.colOptions?.type === RelationTypes.BELONGS_TO && tableMeta?.mm) {
+      return true;
+    }
+    // hide system columns in other tables which are has-many used for mm
+    return col.colOptions?.type === RelationTypes.HAS_MANY;
+  }
+
+  return ([UITypes.CreatedBy, UITypes.LastModifiedBy] as string[]).includes(
+    col.uidt
   );
 }