If you want only those applications that have used the DP code and have not used the DI code, then:
1-Record Select: {act.act_cd} in ["DP","DI"]
2-Group on {app.opr_app_nr}
3-Create a formula {@DPDIvalue}, place in details section, and suppress:
if {act.act_cd} = "DP" then 100 else
if {act.act_cd} = "DI" then 1
(If it is possible to have more than 100 instances of "DI" then change the 100 to 1000 in the formula above and below.)
4-Add the following Group Select:
remainder(sum({@DPDIvalue},{app.opr_app_nr}),100)= 0
-LB