How to pass the exception caught in inner catch to outer catch in a nested try catch

I am nesting try catches inside of a main try catch statement, what I would like to know is how I can make the main try catch fail if one of the nested try catches fails?

Here is my code:

try 
{    
    try 
    {
        //how can I make the main try catch fail if this try catch fails?
    } 
    catch(Exception $e)
    {
        error_log();
    }       
} 
catch(Exception $e)
{
    error_log();
}