import re
textToSearch = """
hello{
@hi {
I want this text
}
@hola {
I don't want this text
}
}
"""
regex= r'[^\S\r\n]*@hi\b[^\S\r\n]*{[^{}]*}'
result = re.findall(regex,textToSearch)
print(result)
aW1wb3J0IHJlCgp0ZXh0VG9TZWFyY2ggPSAiIiIgCmhlbGxvewogICAgQGhpIHsKICAgICAgICBJIHdhbnQgdGhpcyB0ZXh0CiAgICB9CgogICAgQGhvbGEgewogICAgICAgIEkgZG9uJ3Qgd2FudCB0aGlzIHRleHQKICAgIH0KfSAKIiIiCgpyZWdleD0gcidbXlxTXHJcbl0qQGhpXGJbXlxTXHJcbl0qe1tee31dKn0nCnJlc3VsdCA9IHJlLmZpbmRhbGwocmVnZXgsdGV4dFRvU2VhcmNoKQoKcHJpbnQocmVzdWx0KSA=