Takayama-Hokuriku Area Tourist Pass

Can i use Takayama-Hokuriku pass for my 5 days as below?
Day 1: Kyoto - Kanazawa
Day 2: Kanazawa - Gokayama (bus). Stay in Gokayama
Day 3: Gokayama - Shirakawa-go (bus) - Takayama
Day 4: Takayama - Nagoya
Day 5: Nagoya - Osaka or Takayama - Osaka
Thank you!

There are two problems with your itinerary:

Day 3: Gokayama - Shirakawa-go (bus) - Takayama

The buses between Kanazawa and Shirakawago cannot be used just between Gokayama and Shirakawago. You could theoretically do the trip by returning from Gokayama to Kanazawa and then again take a bus from Kanazawa to Shirakawago.

The timetables:
http://www.japan-guide.com/bus/shirakawago.html

Day 5: Nagoya - Osaka or Takayama - Osaka

The pass does not cover the trains between Nagoya and Osaka or Takayama and Osaka. You would have to return via Kanazawa in order for the pass to cover the entire journey.

The pass and its coverage area are explained here:
http://www.japan-guide.com/e/e2361_takayama_hokuriku.html

I don't know about whether you can stopover in Gokayama using the Pass.
In order to go from Gokayama to Shirakawa-go, you will need to pay the extra charge. In that section, you will be riding the bus of other bus company.

Gokayama (Ainokura or Suganuma) - Shirakawago:
http://www.japan-guide.com/bus/gokayama.html

I think if you know, in order to return directly to Kyoto or Osaka from Nagoya via bullet train or Tokaido Line, you must pay a separate fee.

Takayama-Hokuriku Area Tourist Pass:
http://touristpass.jp/en/takayama_hokuriku/

So how about this itinerary?
Day 1: Kyoto - Takayama - Nagoya (stay in Nagoya)
Day 2: Nagoya - Takayama - Shirakawago - Takayama
Day 3: Takayama - Gokayama (stay in Suganama)
Day 4: Gokayama - Kanazawa
Day 5: Kanazawa - Osaka
I'd like to know that buses from Takayama - Shirakawa-go, Takayama - Gokayama and Gokayama - Kanazawa still covered Takayama-Hokuriku Tourist Pass? Thanks

Day 1:
I recommend that you go to Nagoya directly by paying another fee. I think the above route is detour.

Takayama - Shirakawa-go: covered
Takayama - Gokayama via Shirakawa-go: not covered
The bus to Kanazawa departs from Takayama stop at Gokayama. However, the bus stop is a ride only. In order to go to Gokayama, it is necessary to transfer to Kaetsuno bus at Shirakawa-go.
Gokayama - Kanazawa: There is no information. The web site for the pass, it is not mentioned about Gokayama.

Thank for your answer, i'll arrange itinerary

I'd like to ask 1 more question that:
Does this Pass cover bus from Kanazawa to Shirakawa-go? Thanks.

yes, it is covered