Steps

• Install the OS X command line tools

xcode-select --install

• Install homebrew

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
brew update

• Install dependencies

brew install automake berkeley-db4 libtool boost --c++11 miniupnpc openssl pkg-config protobuf python3 qt libevent

• Install qt-creator

brew cask install qt-creator

• Clone bitcoin core

git clone https://github.com/bitcoin/bitcoin
cd bitcoin

• Add config file

mkdir conf
touch conf/bitcoin.conf
vim conf/bitcoin.conf
=====
regtest=1

rpcuser=btc
rpcpassword=btc

listen=1
server=1
=====

• Execute autogen.sh

./autogen.sh

• Execute configure

./configure --enable-debug

• Import project in qt-creator

Menu "File" ->
Select "Open File or Project" -> 
Select "Makefile.am" -> 
Button "Open" ->

• Open Tab "Projects"

• Modify "Manage Kits"

• Modify "Run"

• Happy debugging...

Reference

bitcoin doc: Mac OS X Build Instructions and Notes