To insert a filter on List webpart by HTML Form webpart in SharePoint 2010,
1. Insert a HTML Form editor webpart on the same page where we have list that we want to filter.
2. Point to HTML webpart, click the 'down arrow', click 'connections' and point to 'Provide form value to' option.
3. Click the name of the webpart to which we want filter
4. In the 'Choose Connection' dialog box and click the 'Configure Connection' tab.
5. In the 'Form Connection Type' menu, select the field that matches the information from the HTML Form webpart
6. Click Finish.