Welcome to the Community. While I'm more of a domains guy, I think I've got two quick answers for you.
I hope that helps,
Thomas D. - GoDaddy | Community Moderator
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The correct answer to this question is that the tenant has a terabyte of storage over and above the individual terabyte that each user has. So if a company has 5 paid users, their tenant would have six terabytes of total storage, although this storage is not shared.
The storage that the groups are using can be viewed on a per group basis as follows: