Dear,
In order to check the building displacement for each floor in Etabs, you have to show the deformed shape for the building for the load case which cause the lateral displacement or find the story drift in the display menu - show table (ex, Seismic in x direction. if you are using the UBC97 as reference, refer to item no. 1630.10.2 to find the maximum allowable drift for each story and your building.