How to configure ccap

I am newbie in S2 member pro.
I have set up level 0 and level 1. I would like that a customer can access two products (pages)
In pay pal (buy now) I have entered a, b
In the first page I have entered in Require Custom Capabilities? box letter “a” and on the second page letter “b”.
Then I have created pay pal button for level 1 with insertion at Custom Capabilities (comma-delimited) field a,b.

Is this correct for a customer to access only a or b pages or both.
I would like that a customer can access only page a or only page b.
Thanks
Andrew

To access all “a” pages, the customer needs to have “a” ccap. There is no matter how much other ccaps he have. So everyone with “a” ccap will access “a” pages. If he has “a” and “b” ccaps, he will access both “a” and “b” pages (and no matter if he purchased “a, then b”, or “b, then a”, or both). So you think accordingly and set payment shortcodes.