If you want to modify the contents of the < title/> tag in the layout dynamically and populate it with the value from a current item’s field, the following steps should be completed.
1. Create a rendering that will simply output the field value of the current item:
<sc:text field="title" /> 2. Add the rendering definition inside of the < title/> tag:

<title>

<sc:xslfile ID="pageTitle" runat="server" renderingid="{C954895B-655A-4C6C-8641-3B199CCDC2D9}"

path="/xsl/Page Title.xslt" />

</title>

To make it more easy you can drop this rendering on your layout in the Layout Studio, then cut-paste it into the < title/> tag.