CAN ONE DO HITBODEDUT TO HASHEM ON YOM TOV?
Yes, this is fine.
For those who practice it the concept of Hisbodedus draws a person to Hashem and embodies the personal closeness between man and his G-d.
There is no reason to refrain from this on Yom Tov, provided of course that a person rejoices with his community in prayer and Hallel and with his family etc. in meals.