When Layer Effects are applied to a layer, the effects are displayed in a list under the layer in the Layers panel. Depending on how many effects are applied, as well as how many layers have these effects, the Layers panel can quickly become crowded.
To collapse the Layer Effects stack, in the Layers panel, click the disclosure triangle to the right of the fx icon.
To collapse all Layer Effects, Option-click (Mac) | Alt -click (Win) the disclosure triangle to the right of the fx icon.
To collapse Layer Effects when they’re added, from the Layers panel fly-out menu, select Panel Options and uncheck Expand New Effects.