About Selecting Objects Based on Shared Properties
A simple method to select objects based on properties such as layer, color, or lineweight, is Select Similar command, accessible from the shortcut menu after you've selected an object.
Quick Select (QSELECT), always accessible from the shortcut menu, offers more options and additional properties, such as transparency, for creating selection sets on the fly.
To create saved selection filters, use the FILTER command or enter 'filter at the Select Objects prompt.