Follow the below steps to enable the Document Sets feature, create and configure a Document Set content type and add it to a Document Library.

• Scroll down to Document Sets and click on the Activate button. Wait for a few seconds to activate, A button labeled Active appears after the feature is activated. 

Create a new Document Set content type in Site Collection

 

• Navigate to the site, click the Gear Icon (Settings icon) in the top-right and select Site information.
• Click on View all site settings.
• In the Site Settings page, Under Web Designer Galleries, click Site content types.

• On the Content type gallery page, click Create content type.
• In the Name box, type the name to your new Document Set (ex: Project). This is the name that users will see when they create a new instance of a Document Set in a document library.
• Under Select parent content type from, click Document Set Content Types. (If the Document Set Content Types option is not listed, the Document Sets feature may not be activated for this site collection).
• Click Create button to create the new Document Set content type. Now you can configure and add columns in the newly created content type. 

Add metadata columns to the Document Set content type

 

• Go to the Site Settings page, Under Web Designer Galleries, click Site content types.
• On the Content type gallery page, search and find the content type by name (in our case, the content type is Project), click the name of the Document Set content type to configure columns.

• Add required Site columns by creating a new site column or selecting existing site column. In my case, I have just added two columns (Project Title and Project Manager).

Add and Configure Document Set content type in a Document Library

 

• Navigate to the document library where you want to add the document set feature. Click the Gear Icon (Settings) in the top-right and select Library settings.
• In the Library Settings page, under the General Settings section, click on the Advanced Settings link.

• In the Advanced Settings page, under Content Types section, choose Yes to Allow management of content types, click OK at the bottom of the screen to save the settings. This will allow us to add custom content types.

• As a result of the above change, you will see the section Content Types on the Library Settings page. Under Content Types section, click the “Add from existing site content types” link to proceed next.

• In the Add Content Types page, select your document set content type (In my case, “Project”) and click Add button to move into the right panel, click the OK button to save the changes.

• Now the document set content type is successfully added to the library.
• In the Library Settings page, you can see the new content type under Content Types section, click on the new content type name (ex: Project) to configure settings.

• On the next page, click Document Set Settings to configure Shared and Welcome page columns.

• In the Document Set Settings page, scroll down to Shared Columns section, you can select the required columns to propagate the metadata details to the files uploaded into the document set. Also, you can configure the Welcome Page Columns, the columns to show on the welcome page for the Document Set.

• Finally, scroll down to the bottom of the page and click OK to save the changes.

Once you created and configured a document set content type in a document library, follow the below steps to create a new instance for the document set in the document library.

As already said, the Document Set is a special kind of folder, you can simply open it and upload the required files.

Enable Document Sets feature in Site Collection
• • Navigate to the site collection root, click the Gear Icon (Settings icon) in the top-right and select Site information.
  • Click on View all site settings.
  • In the Site Settings page, under Site Collection Administration, click Site collection features.