How can I combine selection criteria??

Coding Python Support
1

I would like to select objects which are on a specific layer AND in a certain group at the same time.

How could I do that?

I only found bpy.ops.object.select_grouped(), where I can define 1 selection criterion.

Many thanks for help!

2 
import bpy

grp = bpy.data.groups["Group"]
layer_num = 0
sce = bpy.context.scene

# Deselect everything
bpy.ops.object.select_all(action='DESELECT')

# Enable target layer (optional)
sce.layers = [False] * 20
sce.layers[layer_num] = True

found = False
for ob in grp.objects:
    if ob.layers[layer_num]:
        print(ob.name)
        ob.select = True
        
        # Make one object active
        if not found:
            found = True
            sce.objects.active = ob