Pulling and joining single field data from parent files

Dear Users, I need your supports on this.
I have a parent file and a linked child file, both created in xls.

Parent file has the structure below:

type name label

|begin_group LocOnb Location Onboarding
text Loc_Name Company Name
text Address Location Address
text Loc_Rep Location Representative
text Loc_Rep_Phone Phone Number|
integer Loc_with_STPs Number of Sites with STP

begin_repeat STP_Sites ${Loc_Name} STP Site Details
text Site_Name Site Name
text Site_Address Site Address
integer STP_Num Number of STPs at this Location
end_repeat
end_group

The child file has this line that is expected to return a list of Names for all captured locations:

type name label calculation
text Loc_list Locations Listed: join(’ ',instance(‘Locs_form’)/root/data [LocOnb/
Loc_Name])

This line returns all data associated with each location captured in the parent file, including the ones within the repeat cycle.
What I’m getting is " Location_A Address_A Location_A_Rep Location_A_Rep Phone Location_A_Site_1_Name Location_A_Site_1_Address Location_A_Site_1_STP_Nos Location_B Address_B Location_B_Rep Location_B_Rep Phone Location_B_Site_1_Name Location_B_Site_1_Address Location_B_Site_1_STP_Nos
etc.

All I need is just the names of the locations joined together with the separator e.g. Location_A Location_B Location_C

what calculation can get this done for me? I tried concat and got the same result, neither is pick only the location names.

@elvis_pooplogg, did you mean pulling the locations from the repeat group?

No, the location names were not created under repeat groups, but each captured location name now has repeat-group questions attached to it.

The child group needs to pull out all the location names captured in the parent file, only the location name, without any other data attached to each location in the parent file.

@elvis_pooplogg, could you share the relevant part of your XLSForms (both the parent form and the child form) with the community so that the community can also help you?