If you want to update your themes by a site group go to: MainWP > Sites > Manage tab. In the dropdown menu select wanted site group and click Display button: Select wanted sites in the group, chose the Update Themes bulk action in the dropdown menu and click Apply button:  

If you want to update your plugins by a site group go to: MainWP > Sites > Manage tab. In the dropdown menu select wanted site group and click Display button: Select wanted sites in the group, chose the Update Plugins bulk action in the dropdown menu and click Apply button:

If you want to ignore Updates for individual Child Sites go to the Child Site edit tab and locate the ignore options in the General Options box: Set this options to YES and click the Update Site button on the bottom of the page. With this option enabled MainWP Dashboard will ignore all Updates for the Child Site. [box] You can ignore Core, Plugin or Theme Updates separately. [box]  

If you use a premium theme or plugins on your child site and automated updates are not available, you can upload and update them from your dashboard. To do that go to the Themes (Plugins) > Install Page. Click the Upload tab: Click the Upload Now button and upload your theme from your computer. After that select wanted sites. Make sure the Overwrite Existing options is checked and click the Install Now button: Your Theme (Plugin) will be overwritten by the newer version!

  If you want MainWP dashboard to update Plugins and/or Themes automatically for you, you need to enable the Auto Updates feature and to mark plugins (themes) you trust to be automatically updated. Enabling Auto Updates Feature To enable auto updates, go to: MainWP> Settings> Global option tab and locate the Upgrade options box: In Automatic daily update box choose Install Trusted Updates option and click the Save Settings button in the bottom of the page. Marking Plugins (Themes) as trusted [box]Setting a Plugin or Theme as Trusted means that YOU trust this plugin/theme and its developer and are choosing

By default updates in the MainWP Dashboard appear in a per plugin view. This means that if you list all your available updates in the right now widget the list will show all your plugins with available updates. You can switch this view and show the updates per site if you prefer. To do this , go to the MainWP > Settings > Global options tab, locked the Upgrade options box and set the View upgrades per site to YES: After switching the view mode your widget will look like this: Updates are now listed per site. Choose the best