How to solve this self joining problem?

Here's my fields and data in a business view

Name|Co-Worker|Related

John|Jane

Smith|Ken

Jane|John

In the Do Section of the UBE, I will look in Co-Worker column and if other records have the same value under the Name column then I'll put a letter X in the Related column for that record.

For example, given the above data set, the end result is below. John and Jane are related because John has Jane under his Co-Worker column and vice versa, Jane has John under her Co-Worker column. So John and Jane have X in the Related column. Smith does not have any records that have Ken so Smith does not have letter X