=IF(COUNTIF([@PCP],"*"&[@Rendering]&"*")>0,"YES","")

Smith, John MD         Brown, Bob MD
Jones, Mike MD         Green, Ann MD
Doe, Jane MD           White, Mary MD

Rendering              PCP                     Seen PCP/team?
---------------------------------------------------------------
Smith                  Smith, John MD          YES
Smith                  Jones, Mike MD          YES
Brown                  Smith, John MD
Green                  Brown, Bob MD           YES
Doe                    White, Mary MD
Doe                    Jones, Mike MD          YES

=IF(@PCP = Smith AND @Rendering = Smith, "YES", IF(@PCP = Smith AND @Rendering = Jones, "YES", IF(@PCP = Smith AND @Rendering = Doe, "YES", IF(@PCP = Jones AND @Rendering = Jones, "YES", IF(@PCP = Jones AND @Rendering = Smith, "YES", IF(@PCP = Jones AND @Rendering = Doe, "YES", IF(@PCP = Doe AND @Rendering = Doe, "YES", IF(@PCP = Doe AND @Rendering = Smith, "YES", IF(@PCP = Doe AND @Rendering = Jones, "YES", "")))))))))