The ornamental design for furniture side panel, as shown and described.
1. Furniture side panel
1.1: Perspective
1.2: Enlarged
The design shows a furniture side panel with an actuating-arm drive for furniture flaps with a setting scale; view 1.2is an enlarged view of the scale of view 1.1, the enlarged view 1.2being taken from the left side under the actuating-arm drive; broken lines in view 1.2indicate matter for which protection is not sought.