JS:
----
import { LightningElement,api } from 'lwc';
import TITLE_FIELD from '@salesforce/schema/Contact.Title';
export default class RecordEditFormLWC extends LightningElement {
// Expose a field to make it available in the template
    selectedValues = TITLE_FIELD; //t to store in a title text field
    // Flexipage provides recordId and objectApiName
    @api recordId;
    @api objectApiName;
    value = [];
    get options() {
        return [
            { label: 'Ross', value: 'option1' },
            { label: 'Rachel', value: 'option2' },
        ];
    }
    get selectedValue() {
        return this.value.join(',');
        console.log('selected values are '+value);
    }
    handleChange(e) {
        this.value = e.detail.value;
    }
}

HTML:
-------
<template>
<lightning-record-edit-form
    object-api-name="Contact"
    record-id={recordId}>
    
 <lightning-checkbox-group name="Checkbox Group"
                              label="Checkbox Group"
                              options={options}
                              value={value}
                              onchange={handleChange}></lightning-checkbox-group>
                                  <p>Selected Values are: {selectedValues}</p>
<lightning-input-field field-name={selectedValue}></lightning-input-field>
    <div class="slds-var-m-top_medium">
        <lightning-button variant="brand" type="submit" label="Save">
        </lightning-button>
    </div>
</lightning-record-edit-form>
</template>