You could wrap your query in a function_score query. This query allows you to provide a filter. Any document that matches the filter (in addition to your original query) will get their score modified according to a boost_mode and a weight. By setting boost_mode to multiply and weight to 100, those documents matching the filter will get their score multiplied by 100. Like this:
GET _search
{
"query": {
"function_score": {
"query": {
"bool": {
"must": [
{
"bool": {
"should": [
{
"multi_match": {
"type": "best_fields",
"query": "exampleKeyword",
"fields": [
"exampleField1^0",
"exampleField2^50",
"exampleField3^10",
"exampleField4^10",
"exampleField5^5"
],
"boost": 50
}
}
]
}
}
]
}
},
"functions": [
{
"filter": {
"terms": {
"Field6": [
1,
2,
3,
42
]
}
},
"weight": 100
}
],
"boost_mode": "multiply"
}
}
}