Two Xbox’s same account & live play each other ?

You can't sign in and play on 2 consoles at the same time with the same account, so you would need separate accounts. But you can share games/Gold with another account through the Home setting. So you would want to set the console your husband would be using as your Home, and then you can use the other console. https://support.xbox.com/en-US/help/hardware-network/console/my-home-xbox

same thing if they just want to play xbox live private game against each other, got to have two copies of the disks?

You can't play on two consoles at the same time with the same account. So technically they could still each use the same account, but if one of them is playing a game, they will be kicked off if the other person signs into the account to play. It's best to create separate accounts for each user.

Thanks for this detailed guidance.

I have done as you suggested and i think the issue of sharing my Xbox Live/Ultimate Pass may be resolved

BUT

It still won't let us play on two different Xbox's at the same time when one Xbox is logged in under my main account, and the other is logged as the other user profile (under same main account). It tells me I can only play one game at a time?! I always use to be able to play same or different games on two different consoles at same time using linked account/profiles on each console.

It is possible for two people in the same house to play together and with other friends on multiplayer online as long as they both have xbox live gold memberships, they would each need their own copy of the game