You can use trigonometry to position your buttons - here’s how!

I’ve labelled the radii of the two circles in your UI; rA is the radius of the inner circle, and rB is the radius of the outer circle.
We want to find the radius of this circle, which goes nicely between those two:

Simple enough - we just take the average of the two radii, so r = (rA + rB) ÷ 2.
Assuming the radius of your inner circle is 0.1 and the radius of the outer circle is 0.15, r = 0.125 (in scale coordinates)
We can then use the parametric circle equations to get our coordinates for our buttons!
x = 0.125 cos(t)
y = 0.125 sin(t)
So what values of t to use? Depends how many menu items you want! I’ll assume you’re going to have 5 menu items - we’ll add 2 to that number and call it n.
Now, we know that when t = 360°, we’ve done a full turn. We have a quarter of a circle here, so we want to have values between t = 0 and t = 90°.
To find the coordinates of each menu item, we’ll use this knowledge to get the coordinates! For each menu item, 1 to 5, we’ll have a number m which represents this menu item (the first menu item is 1, second is 2, and so on).
We’ll now divide 90 by n and multiply by m, to get 90m/n for our value of t. So the coordinates of the first menu item are:
t = 90/7 °
x = 0.125 cos(90/7 °) = 0.12186…
y = 0.125 sin(90/7 °) = 0.02781… (edit: Roblox flips the Y axis, so you’ll want to make this number negative)
You can plug those coordinates in to your buttons’ Positions to make them line up perfectly! Something to note - when you do this, the buttons will start due east and go anticlockwise, so make sure you do it in reverse order:
