TEXTJOIN - getting 1 occurrence of duplicate values only

Hi,
I have searched the forum, but no similar problem found.

Underlying code returns the info I want, but has doubles.
I would want to see only occurrence of each value.

ActiveCell.FormulaArray = "=TEXTJOIN(""" & Delimit & """,TRUE,IF(" & LookUpRange & " = " & LookUpValue & "," & ResultRange & ",""""))" which results in this formula:

=TEXTJOIN(", ";TRUE;IF(($B$2:$B$30=G6);$C$2:$C$30;""))

However I would want to see 1 occurrence of every duplicate values only.
See attachment. In example I want the outpu as in Cell I4 and I6, instead of the formula resulting in H4 and I4.
Found different leads, but can't figure out a simple answer.

Any help appreciated.
A