Jmeter - Regular Expression Extractor

I'm new to jmeter and I'm facing an issue with Regular Expression Extractor.

Details:
Http request: /apps/Account/LogOn/TestFirm

This is the response I've received (I've edited for security purpose). The response from the result tree appears to be from redirected message, probably its hidden response.

<html><head><title>Object moved</title></head><body>
<h2>Object moved to <a href="https://xxxxxxx.xxxx.xx.xxx.com/idp/xxxxx?ClientID=LandingPage_Dev&amp;SAMLRequest=fZJR...................CWfsOv17a4G70I2zPlSTrKdX3%2F7G9TM3D">here</a>.</h2>
</body></html>
!DOCTYPE html>

Now I need to capture SAMLRequest and I've used Regular Expression Extractor with the below information:

Reference Name: SAMLRequest
Regular Expression: SAMLRequest=(.+?)">here 
Template: $1$
Match no (0 for random): 1
Default value:

And in the following HTTP Request I've used ${SAMLRequest} and in the request message it goes as ${SAMLRequest} instead of the value. I think nothing is being captured.

Can anyone please help me on how to capture the hidden response as shown above?

Also, what is RelayState? Is it applicable here?

Edit:

191 - is where the SAMLRequest is received from the response.
I have added Regular Expression Extractor, I guess here the value is hidden or something?

193 - I'm using ${SAMLRequest} and in the request body I can see

&SAMLRequest=${SAMLRequest}

instead of the actual value.

Solution

You may want to check the "Apply to" checkbox in the Regular expression extractor. This parameter defines which regular expression will be applied to either only main sample results or to the embedded resources too.