Thanks for asking this question. I did not know the solution so I tried something and it worked.
Group1a
Group1b
Group1c - Go to Section Expert, Select Group1c, Hit the Formula (conditional) button and either type in "InRepeatedGroupHeader" or select "InRepeatedGroupHeader" from: Functions|Print State.
I use "InRepeatedGroupHeader" for all my reports to place "Continued" in any repeating group header. (If InRepeatedGroupHeader then "Continued") but I never tried this before.