You can use the Canvas->SizeX/SizeY to get the current resolution of the screen. You can then use these to offset your textures on the screen.
For example, Canvas->SizeX * 0.5f, would be the center of the screen on the X axis, so you could position them based on that. However, I think textures are positioned from the top left, so you would have to take the size of the texture into account.
I’ve found that having a FVector4 that you can edit in a HUD blueprint is helpful, as you can use the X/Y as the position of the texture (offset with Canvas->SizeX/Y to make sure it scales position with resolution) and the Z/W to scale your texture to your recommended size.
There may be many better ways of achieving this, but I haven’t found any and I use this method for now.