I can't figure out what you are trying to explain in your third paragraph but from the first two I believe you are describing a multiplexed common-cathode 7-segment display.
In such a display the anodes of all of the 'a' segments go to one pin, the anodes of all of the 'b' segments go to another pin, etc.
In that same display the cathodes of all of the segments (a, b, c, ...) of the 'ones' digit go to one pin, the cathodes of all of the segments of the 'tens' digit go to another pin, etc.
The segment selection is done with a high level since you are dealing with the LED anodes. The digit selection is done with a low level since you are dealing with the LED cathodes.
Don