i suggest you creating a new map, a “menu map” create a new HUD, and set this HUD as the default HUD for the “menu map”, you can add a “combobox” from the “input” section by just dragging it to the map, you can configure the combo box in this menu in the left side of the screen, you have to bind it to a blueprint and change the graphics based on the option the player chooses, to change the graphics inside blueprint use “get game user settings” and from these settings you can change shadows/Antialiasing/textures etc.
