Connect Web Parts in SharePoint 2010
One cool thing you can do with Web Parts in SharePoint 2010 is connect them to each other. This allows you to use one Web Part to filter the values of another Web Part. This is a very powerful feature that allows you to create useful, data-driven web pages in your team site.
Follow this process to connect two Web Parts:
Add both the Web Parts you want to connect to your Web page.
For example, you can add two List View Web Parts to your page, and use one List View Web Part to filter the other. If you have an Enterprise license for SharePoint 2010, be sure to check out the cool filter Web Parts designed for filtering other Web Parts using a date or free-form text field.
Save your page (choose Page→Stop Editing).
If you don’t save your page first, sometimes you can't connect.
Click the Edit button on the Page tab of the Ribbon to place your page in Edit mode.
Place a check mark in the upper-right corner of the Web Part you want to use as the filter.
On the Ribbon, click the Web Part Tools Options tab and then click Web Part Properties button.
The tool pane appears.
Click the drop-down arrow on the filtering Web Part, choose Connections→Send Row of Data To, and then choose the name of the Web Part you want to filter.
The Choose Connection dialog box appears. The Choose Connection tab displays the connection type that you selected in this step.
Click the Configure Connection tab and then choose the field name you want to filter on from the Consumer Field Name drop-down list.
This is the field that has the set of values you want to match from your filtering Web Part. In this example of filtering a Tasks Web Part with a Date Filter Web Part, chose the Due Date field.
Click the Finish button.
The connection is established. As you select values in one Web Part, the connected Web Part is filtered accordingly.