This ability is described in full on the Army Rules page of Codex: Space Marines.
Each Detachment rule in Codex Supplement: Space Wolves includes a Saga you can complete, with additional effects that apply once you have done so.
Designer’s Note: The rules presented in this section assume that the ADEPTUS ASTARTES units in your army are from the Space Wolves Chapter, but they can also be used to represent any Space Wolves successor Chapter, such as one described in the background section of this book, or even one of your own invention. However, players who wish to faithfully recreate the Space Wolves Chapter on the tabletop should only include SPACE WOLVES EPIC HEROES if their collection is intended to represent the First Founding Chapter itself; Logan Grimnar is the Great Wolf of the Space Wolves, for example, and not of any of their successors.
While this unit is within 6" of one or more friendly SPACE WOLVES CHARACTER models (excluding WULFEN models) or within 12" of one or more friendly WOLF PRIEST models, if it is not Battle‑shocked, add 1 to the Objective Control characteristic of INFANTRY models in it and add 3 to the Objective Control characteristic of VEHICLE models in it.