Let’s think about it with levels of the structure:
Band 1 and 2 people (junior end, no direct reports). Very hands on roles, probably told what to do on a daily/weekly basis or very clear objectives from their manager.
Managed by Band 3 people (line managers). So you have people management responsibility and you probably report up to seniors about the team’s performance, successes and challenges.
The Band 3 people have Band 4 managers but some may have Band 5 managers.
At Band 4 you probably manage the team/department’s budget. You are starting to oversee processes and input at a strategic level.
Let’s say the levels only go up to Band 6.
So Band 5 are senior roles. Here you are definitely setting the direction of your department and responsible for its performance.
One Band 5 manager doesn’t have direct reports but does a unique, specialised role in the business due to their skills, so gets the senior manager title.
Band 6 are so senior they would probably be called directors. They would oversee all the bands below but only directly line manage some of the 5s.
(Not real bands eg NHS levels, just to illustrate.)