To answer your question about:
What values during the hello messages act as
1. P - Prime number
2. G - Generator
3. Secret primes owned by each parties
In the TLS Handshake protocol for DH/DHE, the P and G are found in the ServerKeyExchange message. The secret primes owned by each parties would NEVER be transmitted over the communication channel, otherwise the whole DH key exchange mechanism would be compromised. A good idea would be to use Wireshark to examine the TLS packets. Otherwise, the ServerKeyExchange message would take this message format:
Content Type: 0x16 (1 byte) || TLS Version (2 bytes) || Length of Overall Message (2 bytes) || Handshake Type: 0x0c (2 bytes) || Length of Handshake Message (3 bytes) || DH P Length (2 bytes) || DH P value (variable) || DH G length (2 bytes) || DH G value (variable) || DH Ys Length (2 bytes) || DH Ys value (variable) || Signature (if any) ...
Furthermore, if you want see the computed value (i.e. g^a mod p, where a is the client's secret integer) by the client being sent to the server, you can check the ClientKeyExchange message by identifying the Handshake Type: 0x10.
Note: Ys represents g^b mod p, where b is the server's secret integer. (A good reference could be found here on page 15)