1. Create a formula:
If InStr({Act.Act_Solicitor(s)},";") = 0 then {Act.Act_Solicitor(s)} else left({Act.Act_Solicitor(s)},InStr({Act.Act_Solicitor(s)},";")-1)

2. Insert a group on the above formula.

3. In the new Group Header #1 section, insert a subreport for all matching Solicitor Action records.

4. Right click on the subreport box (in group header #1) and select Change Subreport Links.

5. Select the formula created in step 1 (we want to pass in this value to the subreport).

6. In the subreport select Report/Select Expert and use the following formula:
   InStr({Act.Act_Solicitor(s)},{?Pm-"formula created in step 1") <> 0

7. In the subreport, Insert a group on the "Act.Act_Solicitor(s)" field.