Selection Filter is a simple addon for Google Sheets which allows you to filter out rows and columns based on the contents of their cells. This is accomplished by simply hiding the rows/columns which do not contain specific values that you specify.
Google Sheets already has the functionality to filter data. However, this plugin was born out of the need to filter data in slightly more advanced ways than Google Sheets natively allows. The filtering functionality provided by Google Sheets only allows you to filter out rows based on the values in a column. Selection Filter does this, and also allows you to filter out columns based on the values in a row. Furthermore, the filter in Google Sheets acts upon the entire spreadsheet; if you filter the value "100" out of column B, then every row which contains the value "100" in column B will be hidden. Selection Filter allows you to filter data in a specific range; it is possible, for example, to filter out each row between rows 2 and 5 that contains the value "100" in column B, while leaving rows 6 and on untouched. Please see the screenshots for more concrete examples of the filtering functionality provided by Selection Filter.