Contour goes out of grid in Meshes.jl

I am using Meshes.jl and GLMakie.jl for plotting on irregular grid. Contour of psi[1,:,:] (red lines) goes out of the circular sector. I want to apply contour on this irregular grid (circular sector).

	grid = StructuredGrid(x, z)
	set_theme!(backgroundcolor = :gray90)
	fig, ax, plt = Meshes.viz(grid, color=vec(rho[1,:,:]), alpha=0.8)
	contour!(plt,psi[1,:,:], levels = 0.1:0.1:1, mode = :relative, color=:red)
	contour!(plt,alfsurf[1,:,:], levels = 0.1:0.1:1, mode = :relative, color=:green)
	colsize!(fig.layout, 1, Aspect(1, 1.0))

Here x and z are 270x100 Float32 matrices each. How to keep contour plot within circular sector mesh?