low_search Field Grid and a relationship inside a column of the grid

I saw a similar question from 5 years ago, but I stumble upon the same question concerning low_search and combination with grid field and inside a column with a relationshipship.

Does low_search allow for a combination search of the two?
I presume it would have syntax like this:
search:fieldname_of_grid:child:columnname_in_grid

Does anyone have a lead how to manage a search like this?

The question from 2015:
Channel Entries – searching relationship field?

Or do I need to write a custom filter for this?