This is the 5163rd most frequent Spanish word.
haberlo
"To have it."
Here, 'haberlo' refers to the completion of an action ('lograr') that is addressed in the hypothesis.
Si hubieras estudiado más, podrías haberlo logrado.
If you had studied more, you could have achieved it.
'Haberlo' here serves to form the infinitive perfect ('not having taken advantage') to talk about a past situation.
Me arrepiento de no haberlo aprovechado.
I regret not having taken advantage of it.
'Haberlo' in this instance introduces the perfect infinitive ('having considered'), indicating a missed action in the past.