Probably you are looking for this command by using bitcoin3-cli:
my-linux-shell$ ./bitcoin3-cli getmininginfo
{
  "blocks": 1734,
  "currentblockweight": 4000,
  "currentblocktx": 0,
  "difficulty": 146.5031960599392,
  "networkhashps": 3452306559.707898,
  "pooledtx": 0,
  "chain": "main",
  "warnings": ""
}

Or type "getmininginfo" command in bitcoin3-qt (menu Help / Debug window / Console).