Complex sentence: In 1970 Johnston was dropped from the TV commentary team but continued to appear as a member of the team for the radio broadcasts, "Test Match Special" (TMS) and continued to appear on TMS for the next 22 years.
Split into simpler sentences: In 1970 Johnston was dropped from the TV commentary team but continued to appear as a member of the team for the radio broadcasts, "Test Match Special" (TMS). It was in that capacity that he continued to appear on TMS for the next 22 years.