"Enforce relationship behavior" for my lookup column will be missing, if the Target lookup list and the current list are not on the same web

Question

I am facing this scenario inside my SharePoint server 2013 & sharepoint server 2016. and i am not sure if there is a way to get it fix.

1. i have a site collection of type team site.
2. i added a list name "Dept".
3. i added a lookup site column named "Dept", which reference the "Dept" list.
4. now under the site collection i create a new subsite.
5. then inside the root web and inside the subsite, i added a custom list, where this custom list contain the lookup column named "Dept".
6. now on both lists (on the root web and on the sub site) the lookup column is referencing the "Dept" list correctly.
7. but the only issue i am facing is that when i access the "Dept" list column at the root web list, i can see the Relationship section for the lookup column as follow:-

8. while on the sub-site list , when i access the "Dept" list column the Relationship section was missing..

so can anyone adivce if there is any workaround to force the Relationship for my lookup column on the sub-site ??

Answer 1

There is some limitation of enforce relationship behavior for OOTB lookup column:

• It is not supported when create lookup as Site Columns
• When set Allow multiple values
• When lookup column references data from other site

As mentioned here ,you can use this solution: http://www.sparqube.com/sharepoint-lookup-column/ but it's paid.