Can you compare liking and not liking something. Example: I liked her yesterday but today I don't
Yes, of course you can.
Liking entails an emotional involvement and is something that can change over time.
I hate going to the gym in the summer, for example, but I absolutely like it in the winter.
Another thing you may do: like and dislike something or someone at the same time.
"I like her because she's my childhood friend, but I don't like her in the sense that she steals."
So in that example, you're comparing two feelings, both liking and disliking.
Is that what you're asking, or am I misunderstanding?