group on claim sequence code
create 2 'flag formula
//flaga
if table.claim= 'code.a' then 1
//flagb
if table.claim= 'code.b' then 1
sum each at the group level
sum(@flaga,table.claimsequencecode)
sum(@flagb,table.claimsequencecode)
now create a Running Total to get you count
name=A_Bcount
field to summarize=claimsequencecode
type of summary=distinctcount
evaluate=use a formula
sum(@flaga,table.claimsequencecode)>0 and
sum(@flagb,table.claimsequencecode)>0
reset=never
place in report footer