Jigokudani Monkey Park to Takayama

hello, is it easy to travel from Jigokudani Monkey Park to Takayama?

I would not call it easy. It involves at least two transfers. You have two possible routes:

1) Bus from Monkey Park to Nagano
2) Shinkansen to Toyama
3) Train to Takayama
(probably faster and more expensive)

OR

1) Bus from Monkey Park to Nagano
2) Train to Matsumoto
3) Bus to Takayama
(probably slower and cheaper)

Two other points to note regarding the Matsumoto route:
- the bus needs to be reserved (a recent change for the better),
- the bus timetable only has four services per day with the afternoon services at 1:05 p.m. and 17:45 p.m. It might not be practical/possible to get the 11:55 a.m. bus resulting in mid afternoon or evening arrival.
Not particularly hard, but a bit cumbersome.

Thank you could you please share the website where I can book the seat for the bus?

https://www.alpico.co.jp/en/howtoride/

hey it looks there are no bus between Snow Monkey park and Nagano. could you please help? the website is not so easy to use thank you

The link given was for Matsumoto to Takayama.
For the monkey park to Nagano, that is Nagaden bus - unable to reserve, limited timetable.