1. At the top of Wireshark, in filter, type frame contains "www.", and click Save. The Save Filter popup box appears.
2. Give the filter an appropriate name, such as Monitor Web Traffic, and click OK. The button will now appear to the right of the Filter.
3. If we want or need to remove the button, so we can save a new button, at the top, click Edit and select Preferences, or just Ctrl + Shift + P. The preferences popup box will appear.
4. In the preferences popup box, on the left, select Filter Expressions
5. Here, we can Remove filters (buttons) we no longer need

To confirm this works, with wireshark capturing, and this filter in use, go to any website, and rows should appear in Wireshark.