Before you get too far along with this, you might want to check out @bertabcd1234 ’s CoCoHue app. Last I checked, the built in app didn’t have all of the features available in CoCoHue (especially the ability for the Hue bridges to push changes to Hubitat, and import and activate scenes). I disconnected my Hue bridges from Alexa a couple years ago and only share what I want Alexa to have access to via the Alexa app in Hubitat.
BTW, welcome to the community.
Also, search for Hubitat Package Manager. HPM is an easy way of finding and installing community maintained apps.
If you are hoping to bring scenes into Hubitat, then you'll need to use one of the community integrations rather than the built-in app. I personally use CoCoHue as well to manage my hue integration. With multiple bridges, you'll need to separate instances (one for each bridge). Once that is done, you'll have everything into Hubitat and can decide how you want to share via the Alexa Skill.
Big learning curve. Can’t figure out how to install things yet via package manager. Just relieved I can finally see my lights together and not the antiquated one hub only Alexa rule.