sub appsettings in the appsetting node c#

I am using the app.config file that is created with a console application and I can read the val1 of the key1 using the ConfigurationSettings.AppSettings["key1"].ToString()

<configuration>  
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0" />
    </startup>  
    <appSettings>
        <add key="key1" value="val1" />
        <add key="key2" value="val2" />  
    </appSettings> 
</configuration>

but I have too many keys and values that I want to make them categorized.

I found something that is difficult to use in my application since I want to access the keys in a similar way to the above one

Showing all nodes and can't read a node without getting all the nodes

for example what I want to do:

<appSettings>
    <Section1>
        <add key="key1" value="val1" />
    </Section1>
    <Section2>
        <add key="key1" value="val1" />
    <Section2>
</appSettings>

and if there is a way to access it using ConfigurationSettings.AppSettings["Section1"].["key1"].ToString()