Summary : SharePoint 2013 – Display “Related Items” in Site Columns, How to add a “Related Items” in Site Column in SharePoint 2013 List, Missing “Related Items” Site Column
If you navigate to list settings for your “Tasks” list you would notice a new Column “Related Items”. This is a new Site Column that is a Part of Task Content type by default.
Why would I use this Column?
This is a very useful column from Business prospective. When you create an Item you can simply add a reference (as Lookup) to another Item in same or different list or library as related entity. See how it works SharePoint 2013 – Related Items Site Column
Where is this column?
This Site Column is a part of Hidden group (“_Hidden”) by default and is not be listed in Site Columns. This however is a part of Task Content type by default. So all we need to do is to navigate to “Related Items” Site Column screen
and change the group from _Hidden to Whatever Custom group you want via the Tasks Content Type.
Click on “Tasks” and you would see the following Columns with “Related Items” at the bottom.
Click on Existing Group and then Change the Group this column belongs to. Click OK once done.
Next Navigate to Site Settings and select “Site columns”
In Site Columns select your group with Show Groups filter.
Now you can use this Site column in any list or Library.
How to add this column to a list?
You can add this column in any list or library from the Site Columns using “Add from Existing Site columns” in a list. See the Steps in Detail
SharePoint 2013 – Related Items Site Column