There is some confusion caused by Priority Pass nomenclature.
Priority Pass sells three levels of membership:
Standard (pay $27 for each visit and for each guest)
Standard Plus (10 bundled visits, pay $27 for additional visits or guests)
Prestige (unlimited bundled visits, pay $27 for guests)
Priority Pass Select is not a membership level. It indicates a membership paid for by a financial institution. It could be Standard or Plus or Prestige -and- the number of bundled visits and guest fees can be modified by the sponsor. This makes it very difficult to generalize about the potential cost of visits.
Yes, but to address OP's question, there are no same-day restrictions. No matter which PP you have, visiting two lounges on the same day should cost the same as visiting one lounge on two separate days.