Dad's backing mother for example - that's obvious (8)
I believe the answer is:
apparent
'obvious' is the definition.
(similar in meaning)
'dad's backing mother for example' is the wordplay.
'dad' becomes 'pa' (pa can mean someone's father).
'backing' is a reversal indicator.
'mother for example' becomes 'parent' (mother is a kind of parent).
'pa' in reverse letter order is 'ap'.
'ap'+'parent'='APPARENT'
'that's' acts as a link.
(Other definitions for apparent that I've seen before include "Evident, manifest" , "Conspicuous" , "cut , book written on a page" , "Seeming real or true" , "Visible - plain - presumable" .)