python open file browser to Group directory of blend file?

Question

Is it possible in 2.79 to open the file browser to the internals of a specified blend?

I have a template.blend, that will have several Groups in it. Currently, I have a button that opens the file browser to the directory the template.blend is in.

It's 2 clicks to get to Groups, and I have to rely on the user knowing they should be looking in Group and not Objects or anywhere else.

Selecting a group then appends it to the scene.

Is it possible to open the file browser inside of the blend, so the user is only presented with Groups to append?

A view similar to:

Edit: Possibly related question

Answer 1

Via the link or append operator

Test script, template file as a scene property in way of example, possibly better set as an addon preference.

import bpy
from bpy.props import StringProperty

class HelloWorldPanel(bpy.types.Panel):
    """Creates a Panel in the Object properties window"""
    bl_label = "Hello World Panel"
    bl_idname = "OBJECT_PT_hello"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "scene"

    def draw(self, context):
        layout = self.layout
        scene = context.scene
        col = layout.column()
        col.prop(scene, "template_file")
        # check if fp exists
        col.operator_context = 'INVOKE_DEFAULT'
        if True: 
            # write an op to 
            directory = "%s/Group/" % (scene.template_file)
            op = col.operator("wm.append")
            op.directory = directory
            op.instance_groups = True


def register():
    bpy.types.Scene.template_file = StringProperty(
            subtype='FILE_PATH')

    bpy.utils.register_class(HelloWorldPanel)


def unregister():
    bpy.utils.unregister_class(HelloWorldPanel)
    # del prop


if __name__ == "__main__":
    register()

Alternatively A file test.blend that has 5 groups in it.

>>> fp = "/home/batfinger/Desktop/test.blend"
>>> with bpy.data.libraries.load(fp) as (data_in, data_out):
...     pass
...     

>>> data_in.groups
['Group.004', 'Group.003', 'Group.002', 'Group.001', 'Group']

a group name above can be passed as filename argument to operator as show in Appending an Object Without A Link

Links re linking appending from files.

How to Link/Append a data-block using the Python API?

Import group from external blend file

How to search through multiple Blender files to find a specific object?