The Symmetry/Roller feature () can be added from the model tree under Component>Definitions using the Shape Optimization context menu.

When the Geometric entity level is set to Boundary, it includes no specific settings so you only need to specify the selection of boundaries where it should be valid in the Boundary Selection section. Only straight edges (in 2D) and flat faces (in 3D) can be selected.

For 3D components, the Geometric entity level can be set to Edge, and then you can restrict the deformation of the edge to a plane defined by a normal vector. Only edges spanning less than 3 dimensions can be selected, and the edges have to be adjacent to a Free Shape Shell feature.

Edges and points shared between the feature and Free Shape Boundary, Free Shape Shell, or Polynomial Boundary features will be free to move tangentially to the boundaries that are part of the Symmetry/Roller selection.