Need to extend my Zigbee network

Hi, I have a couple of Orvibo motion and contact sensors (from Banggood). They are working great. However, I can not place them in the corners of my house, because of bad coverage.
Which Zigbee device should I buy that would extend the mesh network Orvibo devices is using?
Would any powered Zigbee device do that?

Thank you very much

Ps. live in Europe :slight_smile: