Alt View Options for Grouping by Multiple Tags?

[Hans-Gunter_Sti]

I have a table with a field "Project" by which is grouped.
It is filtered by a specific project and by records in which the
where the field "Project" is empty. Between some records, the empty
project group and the records of the non-empty project group there is
a relationship in another field.
The goal is to have the records in the empty project group that have a relationship
to the non-empty project group appear together in one view. Is this representable in Airtable?