Enable Metadata Navigation and Filtering:
We can enable Metadata Navigation and Filtering feature for SharePoint site from Manage Site Features. To do that you must be a Site Owner or a Site Collection Administrator.
Now please follow the below steps to activate feature:
1- Go to the Site Actions -> click Site Settings.
2- Under Site Actions -> click Manage site features.
3- From the Features list look for Metadata Navigation and Filtering, and then click Activate.
Feature activated, great.
Now follow below steps to configure this in List or Library.
Setp1: Now go to the list or library for which you want to configure metadata navigation.
Step2: Then click List Settings or Library Settings. Under General Settings, click Metadata navigation settings.
Step3: In the Configure Navigation Hierarchies section, select the field or fields you want to display in the navigation hierarchy and then click Add.
Note: By default, Folders are automatically displayed in the navigation hierarchy. If you do not want folders to display, select Folders, and then click Remove.
Step4: In the Configure Key Filters section, select the fields you want to add as Key Filters, and then click Add. In the Configure automatic column indexing for this list, specify whether you want to automatically create indices on this list to increase the performance of the queries that users will perform when they use the Navigation Hierarchy and Key Filter columns you've specified. It is recommended that you select the option Automatically manage column indices on this list.
=> Then click OK.
To View the filter:
1- Go to All Site Content -> Click on the list -> Now at the left panel we will able to see filter